Effects of LED lighting during incubation on layer and broiler hatchability, chick quality, stress susceptibility and post-hatch growth.

Providing light during incubation has been shown to affect hatchability, but the use of LED lights has not been evaluated. This experiment evaluated the effects of LED lighting during embryogenesis on White Leghorn and commercial broiler eggs. To determine this, two experiments were conducted, the first using White Leghorn eggs (N=3456) and the second using commercial broiler eggs (N=3456) where eggs were incubated 12 h of light and 12 h of darkness (LED) or complete darkness (DARK); the light level was 250 lux. Hatchability, embryo mortality, and chick quality were measured in both studies, and a subset of one of the broiler egg trials were grown out to investigate fear and stress parameters. There was no effect (P>0.05) on hatchability of layer eggs; however, there was a difference (P=0.02) observed in chick quality, with the LED group having more chicks (75.34%) with no defects than the DARK group (56.53%). Broiler eggs exposed to LED light showed an increase in hatchability (90.12%, P=0.03) and an increase in no-defect chick percentage (86.12%, P=0.04) at hatch compared to the DARK chicks (85.76% and 69.43%, respectively). Differences were observed between treatments during the 14 d grow-out. The LED birds had lower (P<0.05) physical asymmetry (0.90±0.05 mm) and heterophil/lymphocyte ratios (0.279±0.021), indicating that they were less susceptible to stress than the DARK birds (1.16±0.07 mm and 0.347±0.021, respectively). There was no difference (P>0.05) observed between treatments in growth, FCR, or fear measures at 14 d. These results indicate that providing LED light during incubation can improve chick quality in both white layer and broiler eggs; however, it only appears to improve hatchability in broilers, which could be related to shell pigmentation. It was also demonstrated that providing LED light during incubation can reduce the stress susceptibility of broilers post-hatch. Utilizing light during incubation may be useful tool for the poultry industry.

Comparison of Two LED Light Bulbs to a Dimmable CFL and their Effects on Broiler Chicken Growth, Stress, and Fear.

The poultry industry is currently undergoing a shift to alternative lighting sources as incandescent lights become less available. While LED and CFL bulbs both have associated increased energy savings, they may affect the bird's growth and well-being differently as they output different light spectrums. To determine how different LED bulbs and a CFL bulb affected broiler performance, behavior, stress, and overall well-being, we conducted an experiment using Cobb broiler chickens (N=360). A NextGen LED bulb (NextGen), a Once Innovations LED bulb (Once), and a dimmable CFL (CFL) were used, all of which had different spectral outputs. Growth and feed conversion, several stress measures, fear tests, organ characteristics, and animal welfare assessment parameters were collected to determine how each light type affected animal well-being. LED treatments had shorter (P<0.05) latency to right during tonic immobility testing when compared to the CFL treatment; however, no other differences (P>0.05) were seen in the other fear tests. The Once treatment resulted in lower composite physical asymmetry, heterophil/lymphocyte ratio, and basal plasma corticosterone concentrations compared to the other treatments (P<0.05). Differences were observed in some organ measures; notably in the eye dimensions of the Once treatment. The Once treatment also had lower (P<0.05) plumage, hock, and footpad scores when compared to CFL treatment, while the Nextgen treatment had lower (P<0.05) plumage and hock scores than the CFL treatment but no difference between the two was seen in foot pad scores. Weight at the end of the growout was not affected by bulb type, however, both LED treatments had increased feed conversion (P<0.05). These results indicate that LEDs can result in better well-being and feed conversion when compared to CFLs. It is also notable that the LEDs did not have the same effects and this is likely due to the spectrum of light each creates. LEDs were shown to improve production and well-being of broiler chickens compared to CFLs.